Furnace



(No Model.) 2 sheets-sheet 1.-

J. SPRINGER.

PURNAGB.

No. 336,765. 0Patented Feb. 23, 1886.

2 Sheets-Sheet 2.

(-No Model.)

' J. SPRINGER.

' FUR'NACB. No. 336,765. Patented Feb.- 23, 1886.V

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.UNITED STATES PATENT OFFICE.

JOHN SPRINGER, OF CLINTON, VISCONSIN.

FU RNACE.

SPECIFICATION forming part of Letters Patent No. 336,765, dated February 23, 1886.

Application filed April 29, i885. Serial No. 163,805. (No model.)

To all whom, it may concern:

Be it known that I, .lor-IN SPRINGER, of Clinton, in the county of Rock and State of \Visconsin, have invented new and useful Improvements in Heating-Furnaces and I do hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawings, which form a part of this specification.

This invention relates to certain new and novel improvements in portable hot-air furnaces.

The invention consists in the peculiar construction of the fire-pot section, in the peculiar construction of the magazine and heatingsection, and in the peculiar construction, arrangement, and combinations of the various parts, all as more fully hereinafter set forth.

Figure l is a central vertical section of my improved furnace. Fig. 2 is a perspective of the base or lire-pot section with parts broken away. Fig. 3 is a vertical section taken at right angles to that of Fig. 1.

In the accompanying drawings, which form a part of this specification, A represents the base of my furnace, upon which is mounted the iirepot section B, which is constructed as follows:

c is an outer cylindrical shell, preferably made of any suitable sheet metal.

b is an inner shell, preferably made of castiron flattened upon two opposite sides, so as to form an air passage or space between such attened sides of the inner shell and the outer shell, a.. \Vithin the inner shell is secured a grate, G, constructed in the form of a coil from suitable piping, the ends of which project through the walls of the fire-pot section B, and may be connected with a suitable water supply or tank, so as to keep a continuous flow of water through the pipe to prevent its burning out, if desired. Below this stationary grate I place an endV shaking grate, D, constructed of serrated bars, the serrations of which project up between the bars of the stationary grate, and above the stationary vgrate I secure in any proper manner the fingered lire-pot E.

Upon the top of the inner or cast-iron section, b, I secure the hollow bridge F, the ends of which communicate with the air-passages c, (see Fig. 2,) while at the longitudinal center of this bridge there is secured the downwardlyprojecting flange G from the lower wall of the bridge, while to the upper wall of the bridge is secured an upwardly-projecting flange, H, the area of which is considerably larger than that of the flange G. Engaging with thislarger flange H, and mounted upon the bridge F, is an inner drum, I, upon the outside of which is secured a spiral flange or blade, J, designed to be inclosed by an outer drum, K, which rests upon the section below, as in the ordinary manner of constructing furnaces of this class, and this drum K is closed at top by a head, L, which is provided upon its under face with the downwardly-projecting flange M, designed to slip over the upper end of the inner drum, I, to close it and shut off communication between the interior of the two drums I and K.

N is an inner drum, which passes down through the head L, the center of the drum I, through the hollow bridge F, and into the flange G at the under side of such bridge. The upper end of this inner drum or flue, N, is designed to be closed by a cap, O, provided with a removable but tightly-fitting cover, P, and from this cap there is secured the laterally- `projecting pipe Q, which communicateswith the smoke-pipe R, which leads to the chimney, and which is secured upon the collar S on the head L, and which communicates with the space within the outer drum. The short connecting-pipe Q is provided with a damper, T.

Communicating with the interior of the drum I and passing out through the head L are one or more pipes, U.

V and W are suitable doors in the fire-pot section, each of which is provided with a sliding damper, as shown.

In practice, and where soft coal or wood is used as fuel, the furnace operates as a surfaceburner as follows: In starting a re in the firepot the damper Tin the pipe Qis opened,which gives a direct draft up through theinner drum. N, and the pipe Q to the smoke-pipe R, and through which the products of combustion pass to the chimney. After the fuel has become well ignited the damper T is closed, which causes the smoke and other products of combustion to pass up on the two sides of the hollow bridge-wall into the drum K, passing up through such drum, and directed by the spi- IOO ral flange J to the exit-pipe S, and thence to the chimney. A greater portion of the heat contained in the products o'f combustion heats the air contained inthe inner drum, I, forcing it out through the hotair pipes U at the top, a fresh supply entering at the bottom, through the air-passages c, up alongside the fire-pot, and through the bridge-Wall, and from thence into the drum I. Vhere hard e coal is to be used as fuel, the central or inner drum, N, may be employed as a magazine, feeding the coal into the saine at the top by removing the cover I).

Vhat I claim as my invention is- 1. In a hot-air furnace, in combination with the Ere-pot section provided with airpassages between such firepot and its inclosingjaeket, a hollow bridge and internal heating-drum, and an inner drum, N, within said drum, substantially as specified.

2. A furnace provided with air-passages bel tween the walls of the fire-pot section, a hollow bridge, an outer and an inner drum eolnmunieating with the combustion-chamber, and an intermediate drum communicating with the hollow bridge, the periphery of such intermediate drum being provided with a spiral4 

